Google Book search-1961-"a sheet nine yards long"

[Sam Clements]

...and it's a sheet of paper(s).

A hit on a book "The Beginnins of the English Newspaper;1620-1660" by Joseph Frank.  p. 239

[* I used "sheet nine yards long" and date: 1959-1964.]

"...more subdued, still showed a superior range and flexiblity, as well as an occasional sparkle of humor.  With a straight face he referred to an indictment of a lawyer that filled a sheet nine yards long, and in his next-to-last number he commented on himself and his colleagues:"  

I don't know if this helps anyone, but thought it was worth posting.

Sam Clements

------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org